Do you think our forefathers had current guns in mind when writing the 2nd Amendment?

The Founding Fathers did not have a crystal ball to know every detail of the future, but the Constitution was written shortly after "the people" of our new country had bested the mightiest military of their time. The Second Amendment was clearly intended to ensure that "the people" would continue to have the means to fight any threat, foreign or domestic.

The Founding Fathers also did not limit their thinking to individual weapons. Warships were the most sophisticated weapons system of the day and the Constitution explicitly recognizes the private ownership of warships in Article 1, Section 8, Clause 11 (Letters of Marque and Reprisal).